The present invention is directed to the operation of a communication device having a transceiver and at least two SIM cards.
It is known in the state of the art that to use GSM telephones a so-called SIM card which enables access to the corresponding networks is needed. In addition to other functions, each SIM card is also equipped with an EEPROM (Electrically Erasable Programmable Read-Only Memory) which contains all the useful, relevant and individual information. Such an EEPROM for example stores the so-called IMSI (International Mobile Subscriber Identification) the PIN (Personal Identification Number) and Super PIN, the international access entitlement, the priority class and the subscriber information.
If a subscriber wants to make a call and turns on his mobile telephone, he is first requested to enter his PIN. If the entered PIN coincides with the PIN stored on the SIM card, it is determined via the IMSI whether the subscriber is properly activated and which additional services he is entitled to use. The subscriber also identifies himself to the network with the MSISDN (Mobile Subscriber Integrated Services Digital Network) radio telephone number stored on the SIM card. By means of the so-called authentication the network then ensures that this is actually an authorized GSM subscriber and after a successful test logs him into the network. The authentication method is based on a comparison of computation results which are determined in parallel on the SIM card and in the network. The computation result is based on a suitable subscriber code which is stored on the SIM card. This individual code is also known to the network side. Both sides process the same input values. Subscriber authentication is provided when the results coincide. Each authentication leads to a new computation which uses a new input value to prevent wrong charges due to manipulation. The calls can only be switched to the xe2x80x9crightxe2x80x9d receiver since the authentication method is used here as well.
In addition to this generally known application, it is also known to equip transceivers with several SIM cards. Such a method is described in greater detail for example in the GB 2345177 application of Nov. 26, 1998. The reason and purpose of using several SIM cards is that if an activated SIM card (logged into the network) is lost, the telephone operation can continue with another SIM card.
One of the principal areas of these applications is the automobile. There the car telephone is almost a series production. So-called navigation systems are also entering the market, which by means of corresponding illustrations inform the driver of the route to his target. Since at present such navigation systems leave much to be desired, devices which take actual changes (such as for example construction sites or traffic jams) into consideration have lately been announced. In that case the corresponding changes are transmitted by a transceiver. This transceiver can also be used to transmit the vehicle""s location, for example of an automobile that was damaged during an accident or was stolen. However, the use of these functions presupposes that the car telephone is logged into the network. But this is not necessarily required. For example a user can change a (car) telephone which is not permanently installed in the car into a mobile telephone by removing it from the holder in the car and using it in his office for example. However if the telephone is permanently built into the car and the user wishes to also receive calls outside of his vehicle with the same car telephone number, there is the possibility of using the car telephone""s SIM card in the normal mobile radio telephone. If a user operates in one or the other manner, updating the navigation system and transmitting vehicle data is only possible when the user inserts the SIM card back into the permanently installed car telephone or inserts the car telephone which he is using as a mobile radio telephone back into the car holder, so that it can communicate again with the navigation installation. But if the user does not insert the SIM card into a permanently installed car telephone, one solution proposes an automatic log-in via another SIM card, for example one that is permanently installed in the navigation unit. This method ensures that certain services remain available via the permanently installed (auxiliary) SIM card, even with a not inserted or logged-in (principal) SIM card. This is particularly advantageous if a logged-in (principal) SIM card is ejected from the holder during an accident, because then an emergency operation is still possible via the less vulnerable, permanently installed (auxiliary) SIM card.
But even this manner of operating is not entirely without problems. Because of the availability of only one transceiver, an alternating operation between a (principal) SIM card and an (auxiliary) SIM card for example can only use the (principal) SIM card or the (auxiliary) SIM card for the data exchange. Thus it is not possible to perform an update of the navigation system with an active (principal) SIM card for example. Nor is the car able to transmit any location data in that case. This can be used by car thieves for example, since the car""s location cannot be determined when any (principal) SIM card is used and the (auxiliary) SIM card is then blocked, although the car can be tracked in principle by means of its components.
The objective of the invention is therefore to present a method whereby the services which are connected to another presently not active SIM card remain available in spite of an active SIM card.
This objective is achieved by a method of operating a communication device with a transceiver and with at least two SIM cards, where only one of these SIM cards is logged into the network, characterized in that the SIM card which is logged-in, reads and/or uses information from the remaining not logged-in SIM card(s). An advantageous further development of the invention is such a method where in order to use functions which are linked to the not logged-in SIM card(s), the call number of the respectively logged-in SIM card is transmitted to the provider of the not logged-in SIM cards, and the provider uses the call number of the respectively logged-in SIM card to ensure that his services are able to function.
If, as set forth above, a SIM card which is logged into the network can access or use information from the other not logged-in SIM card(s), the services which are accessible via the not logged-in SIM card(s) remain available and certain data, which for example can otherwise be used via the not logged-in SIM card, are transmitted to the logged-in SIM card for processing.
It is also possible to inquire about conditions or update through a provider of a not logged-in SIM card, if set forth above call number of the logged-in SIM card is transmitted to the provider of the not logged-in SIM card. In that case the provider can use the call number of the logged-in SIM card to ensure the function of his service without any problems.